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Engine rattle and clack.
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Engine rattle and clack. I recently bought a used 02 WS6 from a car dealer. Engine seemed a little noisy but nothing I haven't heard before in a LS1 car so I bought it. Well it seems the dealer must have added something to the oil to MASK worn rod bearings.
After changing the oil the 1st time I noticed the engine sounded louder and I called the dealer service dept. They listened to it and told me no problems found. Well now after the second oil change ITS REALLY LOUD, every time you let off the gas at about 1500rpms the engines rattles and clacks. This is as you are driving you can hear it!
Its quiet at a idle but if you rev it to about 1500 rpm it rattles and clacks terrible. I'm guessing the second oil change I did completely washed out what ever GOO they tossed in there to quiet it.
I'm going to try and return the car Monday. If they won't take it back I'm going to be in quite a bind. Crazy stuff....never trust a dealer!
After changing the oil the 1st time I noticed the engine sounded louder and I called the dealer service dept. They listened to it and told me no problems found. Well now after the second oil change ITS REALLY LOUD, every time you let off the gas at about 1500rpms the engines rattles and clacks. This is as you are driving you can hear it!
Its quiet at a idle but if you rev it to about 1500 rpm it rattles and clacks terrible. I'm guessing the second oil change I did completely washed out what ever GOO they tossed in there to quiet it.
I'm going to try and return the car Monday. If they won't take it back I'm going to be in quite a bind. Crazy stuff....never trust a dealer!
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Oil was clean and filter looks clean. I have 40 at idle hot and 60 wot hot, BUT lets say you are driving normal at 40mph and let off the throttle as you give it throttle again the engine clatters then its quiet. So basically every time you unload the engine and load it clatters as you give it throttle. If you stay steady on the throttle it stays quiet. I'm positive its worn rod bearing noise.
Only other thing I can think of is some kind of piston-wrist pin noise going on but I'm not sure how to tell the difference. I tried unplugging the fuel injectors on some of the cylinders to see if unloading the piston would change the noise but its very hard to tell.
If I get the engine hot its quiet at idle in park, but as you raise the rpms to about 1500 it starts to clatter loudly then as you get to about 2k it quiets back down.
Only other thing I can think of is some kind of piston-wrist pin noise going on but I'm not sure how to tell the difference. I tried unplugging the fuel injectors on some of the cylinders to see if unloading the piston would change the noise but its very hard to tell.
If I get the engine hot its quiet at idle in park, but as you raise the rpms to about 1500 it starts to clatter loudly then as you get to about 2k it quiets back down.
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Update, this is hard for me to swallow but I'm 99% sure all this noise is PISTON NOISE!
If I drive the car hard up a long grade and get the pistons good and hot the rattle and clacking goes away for a min then comes back.
Anyone ever hear of piston noise this bad? Almost seems impossible but its there.
I'm sure its not worn bearings for two reasons. 1 the oil pressure is 42 hot idle 60 wot and 2 the noise almost goes away if I drive it hard.
Someone else must have experienced this problem. Please post up.
If I drive the car hard up a long grade and get the pistons good and hot the rattle and clacking goes away for a min then comes back.
Anyone ever hear of piston noise this bad? Almost seems impossible but its there.
I'm sure its not worn bearings for two reasons. 1 the oil pressure is 42 hot idle 60 wot and 2 the noise almost goes away if I drive it hard.
Someone else must have experienced this problem. Please post up.
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Yeah I agree but at 1000 rpm in park it sounds like you are shaking a can with marbles in it. Raise the rpms and little and its gone. I've heard this noise in other ls1 engines but only when the engine was cold while accelerating through the gears. Once they warmed up it was quiet.
I'm going to let a local LS1 shop take a quick look at it and see what they think.
I'm going to let a local LS1 shop take a quick look at it and see what they think.
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No its not that but I think there is lifter noise in the mix. At idle you hear the rocking -knocking piston sounds and as you raise the rpms to 1000 something starts to rattle clack badly by 1800 rpms its quiet again. Quite a handful of noise to try and understand.
Tomorrow I'm taking it to a very well known LS1 shop and see what they think. The car runs great and above 2k the engine sounds good.
One more weirdo thing I noticed if I drive really easy sometimes the noise seems to go away<I know that sounds crazy but a few times the engine has gotten quiet. That seems to scream lifter trouble to me. The car only has like 42k miles on it, so it sat a lot over the years. Maybe the lifters have some issues????
I know this much when I tried switching from 10-30 to 10-40 the engine sounded much worse and it started missing at a idle. It clattered so loud at 1000 rpms as I was driving it scared me. Maybe it caused the lifters to collapse? I drained the 10-40 out and put 10-30 back in and the missing stopped and the engine clatters less.
I know quite a feast craziness to digest.
Tomorrow I'm taking it to a very well known LS1 shop and see what they think. The car runs great and above 2k the engine sounds good.
One more weirdo thing I noticed if I drive really easy sometimes the noise seems to go away<I know that sounds crazy but a few times the engine has gotten quiet. That seems to scream lifter trouble to me. The car only has like 42k miles on it, so it sat a lot over the years. Maybe the lifters have some issues????
I know this much when I tried switching from 10-30 to 10-40 the engine sounded much worse and it started missing at a idle. It clattered so loud at 1000 rpms as I was driving it scared me. Maybe it caused the lifters to collapse? I drained the 10-40 out and put 10-30 back in and the missing stopped and the engine clatters less.
I know quite a feast craziness to digest.
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hmm .....very interesting, and I wish I had some sort of explanation to offer but your description of whats going on with the motor seems all over the map.....time to pull the top end apart and look at it I would say....good place to start.
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It is odd because its seems if I drive it harder the piston noise is less(rocking-knocking), If I drive it very easy the lifter noise is less(clacking at 1000 rpm).... I guess that makes sense now that I'm typing it. But I'm still not sure what I'm really hearing making noise.
I did find quite a few posts on the internet about the rattle as you let off the gas and get back on it but I didn't find any diagnoses or solutions. The 5.3 engines seem to have it.
Best way to sum the problem up is a rattle clacking sound as the get on the gas at very light throttle below 1500 rpms. Just a tad harder on the throttle causes the rattle to stop instantly! Its bazzar!
I did find thread on a corvette forum with very similar problems BUT his oil pressure was low. He found worn rod bearings.
What scares me about this mess is before I changed the oil I added some STP and it stopped the noise. <this has me worried. I just can't see how I could have 40 psi oil pressure at idle with worn bearings.
Dealer says there is nothing wrong with it!
A few years ago I was working on a engine that had some weird trouble with its lifters and it turned out that the lifters were getting clogged and not relieving. But my engine is very clean inside, oil looks like new even after a few 100 miles driving.
I found this info about LS1 noise http://www.ls2.com/forums/showthread.php?t=5267
I did find quite a few posts on the internet about the rattle as you let off the gas and get back on it but I didn't find any diagnoses or solutions. The 5.3 engines seem to have it.
Best way to sum the problem up is a rattle clacking sound as the get on the gas at very light throttle below 1500 rpms. Just a tad harder on the throttle causes the rattle to stop instantly! Its bazzar!
I did find thread on a corvette forum with very similar problems BUT his oil pressure was low. He found worn rod bearings.
What scares me about this mess is before I changed the oil I added some STP and it stopped the noise. <this has me worried. I just can't see how I could have 40 psi oil pressure at idle with worn bearings.
Dealer says there is nothing wrong with it!
A few years ago I was working on a engine that had some weird trouble with its lifters and it turned out that the lifters were getting clogged and not relieving. But my engine is very clean inside, oil looks like new even after a few 100 miles driving.
I found this info about LS1 noise http://www.ls2.com/forums/showthread.php?t=5267
Last edited by RockinWs6; Apr 17, 2013 at 12:08 AM.
you're forgetting the fact that your oil gauge is known to be a dummy gauge... They're not accurate at ALL. You could actually HAVE low oil pressure... Get an aftermarket gauge and check it.
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Please read this entire thread, my noise is NOT pinging or detonation.http://www.fullsizechevy.com/forum/g...elerating.html
I see why the dealer is claiming normal noise because this dealer sells a lot of trucks.
Found this post on LS1.com
Quote Originally Posted by 35th-ANV-SS View Post
A quick way to see if it's rod bearings is to drain the oil.
If you have metal shavings in the oil...well
not always the case. i drained mine twice in my '98 and didn't show anything. only after pulling apart the engine and pulling the oil pan could i see shavings. i ended up having 4 spun rod bearings!!! found that out only after i pulled the valve covers, checked the rockers, pushrods, and all was fine. then i pulled the heads and checked all the lifter, again all were fine. that ment only one thing, ROD BEARINGS. pulled the motor, only had to polish the crank journals, and rebuild the engine. all the clearances and tolerances are with GM specs. now the car is quiet, and runs like a beast.
my oil pressure was normal, i wasnt burning/using oil, nothing to indicate spun bearings, but thats what it is. the only sound was the knocking sound that was more apparent from the topside of the engine, not underneath.
the sound was at start up, then would go away once warmed, and show up around 2000rpm. quiet under load/acceleration, but at a sustained/held RPM 2000 or higher the sound was heard.
anyways, i rebuilt my 1st Ls1, and honesty it's not that complicated. just takes time to make sure everything checks out.
I see why the dealer is claiming normal noise because this dealer sells a lot of trucks.
Found this post on LS1.com
Quote Originally Posted by 35th-ANV-SS View Post
A quick way to see if it's rod bearings is to drain the oil.
If you have metal shavings in the oil...well
not always the case. i drained mine twice in my '98 and didn't show anything. only after pulling apart the engine and pulling the oil pan could i see shavings. i ended up having 4 spun rod bearings!!! found that out only after i pulled the valve covers, checked the rockers, pushrods, and all was fine. then i pulled the heads and checked all the lifter, again all were fine. that ment only one thing, ROD BEARINGS. pulled the motor, only had to polish the crank journals, and rebuild the engine. all the clearances and tolerances are with GM specs. now the car is quiet, and runs like a beast.
my oil pressure was normal, i wasnt burning/using oil, nothing to indicate spun bearings, but thats what it is. the only sound was the knocking sound that was more apparent from the topside of the engine, not underneath.
the sound was at start up, then would go away once warmed, and show up around 2000rpm. quiet under load/acceleration, but at a sustained/held RPM 2000 or higher the sound was heard.
anyways, i rebuilt my 1st Ls1, and honesty it's not that complicated. just takes time to make sure everything checks out.
Last edited by RockinWs6; Apr 19, 2013 at 12:14 PM.
Thread Starter
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Please read this entire thread, my noise is NOT pinging or detonation.http://www.fullsizechevy.com/forum/g...elerating.html
I see why the dealer is claiming normal noise because this dealer sells a lot of trucks.
At this link is a corvette with the EXACT same problem with a video. Mine sound EXACTLY like this. http://forums.corvetteforum.com/c5-t...n-revving.html
Found this post on LS1.com
Quote Originally Posted by 35th-ANV-SS View Post
A quick way to see if it's rod bearings is to drain the oil.
If you have metal shavings in the oil...well
not always the case. i drained mine twice in my '98 and didn't show anything. only after pulling apart the engine and pulling the oil pan could i see shavings. i ended up having 4 spun rod bearings!!! found that out only after i pulled the valve covers, checked the rockers, pushrods, and all was fine. then i pulled the heads and checked all the lifter, again all were fine. that ment only one thing, ROD BEARINGS. pulled the motor, only had to polish the crank journals, and rebuild the engine. all the clearances and tolerances are with GM specs. now the car is quiet, and runs like a beast.
my oil pressure was normal, i wasnt burning/using oil, nothing to indicate spun bearings, but thats what it is. the only sound was the knocking sound that was more apparent from the topside of the engine, not underneath.
the sound was at start up, then would go away once warmed, and show up around 2000rpm. quiet under load/acceleration, but at a sustained/held RPM 2000 or higher the sound was heard.
anyways, i rebuilt my 1st Ls1, and honesty it's not that complicated. just takes time to make sure everything checks out.
I see why the dealer is claiming normal noise because this dealer sells a lot of trucks.
At this link is a corvette with the EXACT same problem with a video. Mine sound EXACTLY like this. http://forums.corvetteforum.com/c5-t...n-revving.html
Found this post on LS1.com
Quote Originally Posted by 35th-ANV-SS View Post
A quick way to see if it's rod bearings is to drain the oil.
If you have metal shavings in the oil...well
not always the case. i drained mine twice in my '98 and didn't show anything. only after pulling apart the engine and pulling the oil pan could i see shavings. i ended up having 4 spun rod bearings!!! found that out only after i pulled the valve covers, checked the rockers, pushrods, and all was fine. then i pulled the heads and checked all the lifter, again all were fine. that ment only one thing, ROD BEARINGS. pulled the motor, only had to polish the crank journals, and rebuild the engine. all the clearances and tolerances are with GM specs. now the car is quiet, and runs like a beast.
my oil pressure was normal, i wasnt burning/using oil, nothing to indicate spun bearings, but thats what it is. the only sound was the knocking sound that was more apparent from the topside of the engine, not underneath.
the sound was at start up, then would go away once warmed, and show up around 2000rpm. quiet under load/acceleration, but at a sustained/held RPM 2000 or higher the sound was heard.
anyways, i rebuilt my 1st Ls1, and honesty it's not that complicated. just takes time to make sure everything checks out.
If yours sounds like that video be ready for a spun bearing. Quick way to check is use a heavier oil then 10-30. If it quiets the noise most likely this is what the dealership that sold you it did.
For the record mine started out sounding exactly like this after I accidentally bounced it off the rev limiter. After I pulled the heads, replace the lifters and push rods it still made the noise. After a couple of more checks and a second test drive it sounds like bearing has completely gone.
Thread Starter
TECH Addict
Joined: Mar 2013
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If yours sounds like that video be ready for a spun bearing. Quick way to check is use a heavier oil then 10-30. If it quiets the noise most likely this is what the dealership that sold you it did.
For the record mine started out sounding exactly like this after I accidentally bounced it off the rev limiter. After I pulled the heads, replace the lifters and push rods it still made the noise. After a couple of more checks and a second test drive it sounds like bearing has completely gone.
For the record mine started out sounding exactly like this after I accidentally bounced it off the rev limiter. After I pulled the heads, replace the lifters and push rods it still made the noise. After a couple of more checks and a second test drive it sounds like bearing has completely gone.
Mine was sounding different every time I drove it because the oring was leaking air into the oil. Shop says bearings are ok.
